Lesson plan

PackIt

PackIt is a software data compression utility for archiving and compressing files on the Apple Macintosh platform. It was the first such program to see widespread use on the Mac, and most Mac software archives accepted uploads only in PackIt format for some time. StuffIt, introduced in the summer of 1987, offered much improved compression, and PackIt quickly disappeared. PackIt was written by Harry Chesley to support an online magazine he was writing for at the time, MacDeveloper. To distribute code and sample applications, he needed to archive a number of files into one for transmission. In the original version this was done in a simple manner, simply placing the Finder file information, data fork and resource fork, if present, in a single stream and placing the resulting "block" in the archive. No compression was used, the program was purely an archiver, similar to the Unix tar utility in concept. Like tar, the format did not include an archive header of any sort. To extract the nth file, PackIt had to read past all of the n-1 files first. PackIt II was released in early 1986 and added Huffman encoding. However the encoding was applied after the file had already been "grouped" together, meaning that the compressor had to work on the file as a whole, or not at all.…

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Article summary

PackIt is a software data compression utility for archiving and compressing files on the Apple Macintosh platform. It was the first such program to see widespread use on the Mac, and most Mac software archives accepted uploads only in PackIt format for some time. StuffIt, introduced in the summer of 1987, offered much improved compression, and PackIt quickly disappeared. PackIt was written by Harry Chesley to support an online magazine he was writing for at the time, MacDeveloper. To distribute code and sample applications, he needed to archive a number of files into one for transmission. In the original version this was done in a simple manner, simply placing the Finder file information, data fork and resource fork, if present, in a single stream and placing the resulting "block" in the archive. No compression was used, the program was purely an archiver, similar to the Unix tar utility in concept. Like tar, the format did not include an archive header of any sort. To extract the nth file, PackIt had to read past all of the n-1 files first. PackIt II was released in early 1986 and added Huffman encoding. However the encoding was applied after the file had already been "grouped" together, meaning that the compressor had to work on the file as a whole, or not at all.…

Key claims

  1. release date: 1986 — source: Wikipedia · confidence 0.95
  2. release date: 1986 — source: Wikipedia · confidence 0.95

Discussion questions

  1. Summarise the article in your own words. Which single claim would you verify first, and why?
  2. The record states that the release date is "1986". What evidence would count against this claim?
  3. The record states that the release date is "1986". What evidence would count against this claim?
  4. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
  5. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

Bibliography

  1. Wikipedia https://en.wikipedia.org/w/index.php?oldid=1364850934

Key claims and bibliography are generated from the same tracked claims and sources as the article page.